a. Field of Invention
The invention relates generally to a manually actuated pump dispenser having an improved discharge valve member, and more particularly to such a valve member of elastomeric material capable of a quick shut-off of the discharge and having a slitted valve element for discharging personal use products such as hand lotions or the like.
b. Description of Related Art
The known manually actuated pump dispensers especially those designed for the dispensing of hand lotions, body lotions, liquid soaps, and other viscous products, typically have both inlet and outlet ball check valves for respectively controlling the flow of liquid product into the pump chamber on each piston suction stroke and for controlling the outflow of the liquid product from the pump chamber during each piston compression stroke. Alternatively, such dispensers may include an inlet ball check valve for controlling the flow of liquid product into the pump chamber and a deformable outlet valve disposed adjacent a discharge end of the spout. U.S. Pat. No. 5,447,258 (hereinafter “the '258 Patent”) is exemplary of such a known pump dispenser.
Specifically, as illustrated in FIGS. 2-5 of the '258 Patent, for the conventional spout as therein disclosed, the end of the spout includes a transverse hole 134 covered by an expandable/stretchable cap 135 having an internal annular bead seated within an external annular groove on the spout for maintaining the cap in place (FIG. 2). A discharge opening 136 is located in an end wall of the cap through which product is discharged upon operation of the pump as product flows through both the axial discharge passage 130 of the spout and through transverse hole 134. In order to more securely attach cap 135 in place, a fixed ring 137 is provided in the FIGS. 3, 4 embodiment or a fixed ring 237 is provided for the FIG. 5 embodiment.
The deformable outlet valve (i.e. cap 135) disclosed in FIGS. 2-5 of the '258 Patent is problematic in many respects, in that cap 135 will simply dislodge from the end of the spout upon application of even slight pressure applied through axial passage 130 and transverse hole 134. This is tacitly recognized as the FIGS. 3 to 5 embodiments require a fixed ring 137 or 237 to maintain cap 135 securely mounted in place at the end of the spout. However, the provision of the extra fixed ring 137 or 237 requires an extra part for securing cap 135 during manufacture of the pump dispenser, and further increases the likelihood of the dispenser failing due to dislodgement of cap 135 during repeated pumping operation.
It would therefore be of benefit to provide a pump dispenser including an improved deformable outlet valve which both facilitates assembly of the pump dispenser, and which is securely disposed at an end of the dispenser spout for reducing or virtually eliminating the odds of the valve being dislodged from the spout.
Yet further, as illustrated in FIG. 1 of the '258 Patent, there is disclosed an improved outlet valve assembly including first and second valve bodies 7, 11, respectively. For the dispenser of FIG. 1, as fluid passes from pipe 2 into hole 5, second valve body 11, which is made of flexible synthetic resin, deforms outwardly to discharge the contents of pipe 2 therethrough and thereafter should return to its rest configuration illustrated in FIG. 1.
As discussed above for cap 135 disclosed in FIGS. 2-5 of the '258 Patent, the valve assembly disclosed in FIG. 1 of the '258 Patent is also problematic in many respects, in that after repeated use, the interaction of product against the inner walls of body 11 and product remaining between shaft 6 and body 11 increases the time it takes for body 11 to close around shaft 6 and thereby prevent further product from being discharged. The interaction of product against the inner walls of body 11 can eventually cause the structure forming body 11 to remain in an outwardly deformed configuration. This condition deteriorates the cross-sectional quality of the discharged product, which at the initial use of the dispenser mechanism, is intended to have a predetermined cross-section designed to be ergonomically pleasing to the user and/or designed for a specific end use. Further, the valve assembly disclosed in FIG. 1 of the '258 Patent includes at least three components fitted together for adequate operation, namely first and second valve bodies 7, 11, respectively, and stopper 22, which render the design thereof complex with regard to the manufacture thereof, and which further increase the odds of failure of one or more of the components.
It would therefore be of benefit to provide a pump dispenser having an improved deformable outlet valve which both facilitates easier and more economical manufacture and assembly of the pump dispenser, which provides repeatability in the cross-sectional quality of the discharged product over the life of the pump dispenser, and which is robust in design and efficient to operate. It would also be of benefit to provide a pump dispenser which will quickly respond for sealing the discharge flow path during each piston suction stroke irrespective of the viscosity of the product being dispensed.